Optical imaging lens and electronic device comprising the same

ABSTRACT

In an optical imaging lens set a first lens of positive refractive power has an object-side surface with a convex portion around the optical axis and a convex portion around its periphery, an image-side surface with a convex portion around its periphery, a second lens of negative refractive power has an object-side surface with a concave portion around its periphery, a third lens has an image-side surface with a concave portion around its periphery, a fourth lens has an image-side surface with a convex portion around the optical axis, a fifth lens has an object-side surface with a concave portion around its periphery, a sixth lens has an image-side surface with a concave portion around the optical axis and a convex portion around its periphery. The sum of total five air gaps AAG and a second lens thickness T 2  satisfy AAG/T 2 ≦3.6.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Chinese Patent Application No.201510035045.7, filed on Jan. 23, 2015, the contents of which are herebyincorporated by reference in their entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an optical imaging lens setand an electronic device which includes such optical imaging lens set.Specifically speaking, the present invention is directed to a shorteroptical imaging lens set of six lens elements and a shorter electronicdevice which includes such optical imaging lens set of six lenselements.

2. Description of the Prior Art

In recent years, the popularity of mobile phones and digital camerasmakes the sizes of various portable electronic products reduce quickly,and so does that of the photography modules. The current trend ofresearch is to develop an optical imaging lens set of a shorter lengthwith uncompromised good quality. With the development and shrinkage of acharge coupled device (CCD) or a complementary metal oxide semiconductorelement (CMOS), the optical imaging lens set installed in thephotography module shrinks as well to meet the demands. However, goodand necessary optical properties, such as the system aberrationimprovement, as well as production cost and production feasibilityshould be taken into consideration, too.

U.S. Pat. No. 7,830,620 discloses an optical imaging lens set of sixlens elements. The first lens element has negative refractive power andthe second lens element has positive refractive power. This arrangementmakes the total length too long to be ideal for the size reduction ofthe portable devices. Therefore, how to reduce the total length of aphotographic device, but still maintain good optical performance, is animportant objective to research.

SUMMARY OF THE INVENTION

In light of the above, the present invention proposes an optical imaginglens set that is lightweight, has a low production cost, has an enlargedhalf of field of view, has a high resolution and has high image quality.The optical imaging lens set of six lens elements of the presentinvention from an object side toward an image side in order along anoptical axis has an aperture stop, a first lens element of positiverefractive power, a second lens element of negative refractive power, athird lens element, a fourth lens element, a fifth lens element and asixth lens element. Each lens element has an object-side surface facingtoward an object side as well as an image-side surface facing toward animage side. The optical imaging lens set exclusively has the first lenselement, the second lens element, the third lens element, the fourthlens element, the fifth lens element and the sixth lens element withrefractive power.

The first lens element has an object-side surface with a convex portionin a vicinity of the optical axis and a convex portion in a vicinity ofits periphery, and an image-side surface with a convex portion in avicinity of its periphery. The second lens element has an object-sidesurface with a concave portion in a vicinity of its periphery. The thirdlens element has an image-side surface with a concave portion in avicinity of its periphery. The fourth lens element has an image-sidesurface with a convex portion in a vicinity of the optical axis. Thefifth lens element has an object-side surface with a concave portion ina vicinity of its periphery. The sixth lens element has an image-sidesurface with a concave portion in a vicinity of the optical axis and aconvex portion in a vicinity of its periphery. The sum of all five airgaps AAG between each lens elements from the first lens element to thesixth lens element along the optical axis and a second lens elementthickness T₂ satisfy a relationship AAG/T₂≦3.6.

In the optical imaging lens set of sixth lens elements of the presentinvention, an air gap AG₁₂ between the first lens element and the secondlens element along the optical axis, an air gap AG₃₄ between the thirdlens element and the fourth lens element along the optical axis and anair gap AG₄₅ between the fourth lens element and the fifth lens elementalong the optical axis satisfy a relationship AG₃₄/(AG₁₂+AG₄₅)≦1.5.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₃ of the third lens element along the opticalaxis and a thickness T₅ of the fifth lens element along the optical axissatisfy a relationship 0.75≦T₃/T₅.

In the optical imaging lens set of sixth lens elements of the presentinvention, a total thickness ALT of the first lens element, the secondlens element, the third lens element, the fourth lens element, the fifthlens element and the sixth lens element along the optical axis satisfiesa relationship 9.0≦ALT/AG₁₂+AG₄₅).

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₁ of the first lens element along the opticalaxis satisfies a relationship T₁/T₃≦1.6.

In the optical imaging lens set of sixth lens elements of the presentinvention, a total thickness ALT of the first lens element, the secondlens element, the third lens element, the fourth lens element, the fifthlens element and the sixth lens element along the optical axis and anair gap AG₂₃ between the second lens element and the third lens elementalong the optical axis satisfy a relationship 8.5≦ALT/AG₂₃.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₁ of the first lens element along the opticalaxis and an air gap AG₃₄ between the third lens element and the fourthlens element along the optical axis satisfy a relationship 2.3≦T₁/AG₃₄.

In the optical imaging lens set of sixth lens elements of the presentinvention, an air gap AG₁₂ between the first lens element and the secondlens element along the optical axis and an air gap AG₄₅ between thefourth lens element and the fifth lens element along the optical axissatisfy a relationship T₅/(AG₁₂+AG₄₅)≦3.0.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₃ of the third lens element along the opticalaxis and a thickness T₆ of the sixth lens element along the optical axissatisfy a relationship 0.8≦T₃/T₆.

In the optical imaging lens set of sixth lens elements of the presentinvention, the optical imaging lens set satisfies a relationshipAAG/T₅≦2.0.

In the optical imaging lens set of sixth lens elements of the presentinvention, an air gap AG₁₂ between the first lens element and the secondlens element along the optical axis, an air gap AG₂₃ between the secondlens element and the third lens element along the optical axis and anair gap AG₄₅ between the fourth lens element and the fifth lens elementalong the optical axis satisfy a relationship 0.7≦(AG₁₂+AG₄₅)/AG₂₃.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₁ of the first lens element along the opticalaxis satisfies a relationship 0.65≦T₁/AAG.

In the optical imaging lens set of sixth lens elements of the presentinvention, a total thickness ALT of the first lens element, the secondlens element, the third lens element, the fourth lens element, the fifthlens element and the sixth lens element along the optical axis and anair gap AG₃₄ between the third lens element and the fourth lens elementalong the optical axis satisfy a relationship 9.0≦ALT/AG₃₄.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₃ of the third lens element along the opticalaxis, an air gap AG₁₂ between the first lens element and the second lenselement along the optical axis and an air gap AG₄₅ between the fourthlens element and the fifth lens element along the optical axis satisfy arelationship 1.3≦T₃/(AG₁₂+AG₄₅).

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₅ of the fifth lens element along the opticalaxis and an air gap AG₃₄ between the third lens element and the fourthlens element along the optical axis satisfy a relationship 1.3≦T₅/AG₃₄.

In the optical imaging lens set of sixth lens elements of the presentinvention, a thickness T₁ of the first lens element along the opticalaxis and an air gap AG₂₃ between the second lens element and the thirdlens element along the optical axis satisfies a relationship2.0≦T₁/AG₂₃.

In the optical imaging lens set of sixth lens elements of the presentinvention, an air gap AG₁₂ between the first lens element and the secondlens element along the optical axis and an air gap AG₄₅ between thefourth lens element and the fifth lens element along the optical axissatisfy a relationship T₅/(AG₁₂+AG₄₅)≦3.0.

The present invention also proposes an electronic device which includesthe optical imaging lens set as described above. The electronic deviceincludes a case and an image module disposed in the case. The imagemodule includes an optical imaging lens set as described above, a barrelfor the installation of the optical imaging lens set, a module housingunit for the installation of the barrel, a substrate for theinstallation of the module housing unit and an image sensor disposed atan image side of the optical imaging lens set.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-5 illustrates the methods for determining the surface shapes andfor determining one region is a region in a vicinity of the optical axisor the region in a vicinity of its circular periphery of one lenselement.

FIG. 6 illustrates a first example of the optical imaging lens set ofthe present invention.

FIG. 7A illustrates the longitudinal spherical aberration on the imageplane of the first example.

FIG. 7B illustrates the astigmatic aberration on the sagittal directionof the first example.

FIG. 7C illustrates the astigmatic aberration on the tangentialdirection of the first example.

FIG. 7D illustrates the distortion aberration of the first example.

FIG. 8 illustrates a second example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 9A illustrates the longitudinal spherical aberration on the imageplane of the second example.

FIG. 9B illustrates the astigmatic aberration on the sagittal directionof the second example.

FIG. 9C illustrates the astigmatic aberration on the tangentialdirection of the second example.

FIG. 9D illustrates the distortion aberration of the second example.

FIG. 10 illustrates a third example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 11A illustrates the longitudinal spherical aberration on the imageplane of the third example.

FIG. 11B illustrates the astigmatic aberration on the sagittal directionof the third example.

FIG. 11C illustrates the astigmatic aberration on the tangentialdirection of the third example.

FIG. 11D illustrates the distortion aberration of the third example.

FIG. 12 illustrates a fourth example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 13A illustrates the longitudinal spherical aberration on the imageplane of the fourth example.

FIG. 13B illustrates the astigmatic aberration on the sagittal directionof the fourth example.

FIG. 13C illustrates the astigmatic aberration on the tangentialdirection of the fourth example.

FIG. 13D illustrates the distortion aberration of the fourth example.

FIG. 14 illustrates a fifth example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 15A illustrates the longitudinal spherical aberration on the imageplane of the fifth example.

FIG. 15B illustrates the astigmatic aberration on the sagittal directionof the fifth example.

FIG. 15C illustrates the astigmatic aberration on the tangentialdirection of the fifth example.

FIG. 15D illustrates the distortion aberration of the fifth example.

FIG. 16 illustrates a sixth example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 17A illustrates the longitudinal spherical aberration on the imageplane of the sixth example.

FIG. 17B illustrates the astigmatic aberration on the sagittal directionof the sixth example.

FIG. 17C illustrates the astigmatic aberration on the tangentialdirection of the sixth example.

FIG. 17D illustrates the distortion aberration of the sixth example.

FIG. 18 illustrates a seventh example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 19A illustrates the longitudinal spherical aberration on the imageplane of the seventh example.

FIG. 19B illustrates the astigmatic aberration on the sagittal directionof the seventh example.

FIG. 19C illustrates the astigmatic aberration on the tangentialdirection of the seventh example.

FIG. 19D illustrates the distortion aberration of the seventh example.

FIG. 20 illustrates an eighth example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 21A illustrates the longitudinal spherical aberration on the imageplane of the eighth example.

FIG. 21B illustrates the astigmatic aberration on the sagittal directionof the eighth example.

FIG. 21C illustrates the astigmatic aberration on the tangentialdirection of the eighth example.

FIG. 21D illustrates the distortion aberration of the eighth example.

FIG. 22 illustrates a ninth example of the optical imaging lens set ofsix lens elements of the present invention.

FIG. 23A illustrates the longitudinal spherical aberration on the imageplane of the ninth example.

FIG. 23B illustrates the astigmatic aberration on the sagittal directionof the ninth example.

FIG. 23C illustrates the astigmatic aberration on the tangentialdirection of the ninth example.

FIG. 23D illustrates the distortion aberration of the ninth example.

FIG. 24 illustrates a first preferred example of the portable electronicdevice with an optical imaging lens set of the present invention.

FIG. 25 illustrates a second preferred example of the portableelectronic device with an optical imaging lens set of the presentinvention.

FIG. 26 shows the optical data of the first example of the opticalimaging lens set.

FIG. 27 shows the aspheric surface data of the first example.

FIG. 28 shows the optical data of the second example of the opticalimaging lens set.

FIG. 29 shows the aspheric surface data of the second example.

FIG. 30 shows the optical data of the third example of the opticalimaging lens set.

FIG. 31 shows the aspheric surface data of the third example.

FIG. 32 shows the optical data of the fourth example of the opticalimaging lens set.

FIG. 33 shows the aspheric surface data of the fourth example.

FIG. 34 shows the optical data of the fifth example of the opticalimaging lens set.

FIG. 35 shows the aspheric surface data of the fifth example.

FIG. 36 shows the optical data of the sixth example of the opticalimaging lens set.

FIG. 37 shows the aspheric surface data of the sixth example.

FIG. 38 shows the optical data of the seventh example of the opticalimaging lens set.

FIG. 39 shows the aspheric surface data of the seventh example.

FIG. 40 shows the optical data of the eighth example of the opticalimaging lens set.

FIG. 41 shows the aspheric surface data of the eighth example.

FIG. 42 shows the optical data of the ninth example of the opticalimaging lens set.

FIG. 43 shows the aspheric surface data of the ninth example.

FIG. 44 shows some important ratios in the examples.

DETAILED DESCRIPTION

Before the detailed description of the present invention, the firstthing to be noticed is that in the present invention, similar (notnecessarily identical) elements are labeled as the same numeralreferences. In the entire present specification, “a certain lens elementhas negative/positive refractive power” refers to the part in a vicinityof the optical axis of the lens element has negative/positive refractivepower calculated by Gaussian optical theory. An object-side/image-sidesurface refers to the region which allows imaging light passing through,in the drawing, imaging light includes Lc (chief ray) and Lm (marginalray). As shown in FIG. 1, the optical axis is “I” and the lens elementis symmetrical with respect to the optical axis I. The region A thatnear the optical axis and for light to pass through is the region in avicinity of the optical axis, and the region C that the marginal raypassing through is the region in a vicinity of a certain lens element'scircular periphery. In addition, the lens element may include anextension part E for the lens element to be installed in an opticalimaging lens set (that is the region outside the region C perpendicularto the optical axis). Ideally speaking, no light would pass through theextension part, and the actual structure and shape of the extension partis not limited to this and may have other variations. For the reason ofsimplicity, the extension part is not illustrated in the followingexamples. More, precisely, the method for determining the surface shapesor the region in a vicinity of the optical axis, the region in avicinity of its circular periphery and other regions is described in thefollowing paragraphs:

1. FIG. 1 is a radial cross-sectional view of a lens element. Beforedetermining boundaries of those aforesaid portions, two referentialpoints should be defined first, middle point and conversion point. Themiddle point of a surface of a lens element is a point of intersectionof that surface and the optical axis. The conversion point is a point ona surface of a lens element, where the tangent line of that point isperpendicular to the optical axis. Additionally, if multiple conversionpoints appear on one single surface, then these conversion points aresequentially named along the radial direction of the surface withnumbers starting from the first conversion point. For instance, thefirst conversion point (closest one to the optical axis), the secondconversion point, and the N^(th) conversion point (farthest one to theoptical axis within the scope of the clear aperture of the surface). Theportion of a surface of the lens element between the middle point andthe first conversion point is defined as the portion in a vicinity ofthe optical axis. The portion located radially outside of the N^(th)conversion point (but still within the scope of the clear aperture) isdefined as the portion in a vicinity of a periphery of the lens element.In some embodiments, there are other portions existing between theportion in a vicinity of the optical axis and the portion in a vicinityof a periphery of the lens element; the numbers of portions depend onthe numbers of the conversion point(s). In addition, the radius of theclear aperture (or a so-called effective radius) of a surface is definedas the radial distance from the optical axis I to a point ofintersection of the marginal ray Lm and the surface of the lens element.2. Referring to FIG. 2, determining the shape of a portion is convex orconcave depends on whether a collimated ray passing through that portionconverges or diverges. That is, while applying a collimated ray to aportion to be determined in terms of shape, the collimated ray passingthrough that portion will be bended and the ray itself or its extensionline will eventually meet the optical axis. The shape of that portioncan be determined by whether the ray or its extension line meets(intersects) the optical axis (focal point) at the object-side orimage-side. For instance, if the ray itself intersects the optical axisat the image side of the lens element after passing through a portion,i.e. the focal point of this ray is at the image side (see point R inFIG. 2), the portion will be determined as having a convex shape. On thecontrary, if the ray diverges after passing through a portion, theextension line of the ray intersects the optical axis at the object sideof the lens element, i.e. the focal point of the ray is at the objectside (see point M in FIG. 2), that portion will be determined as havinga concave shape. Therefore, referring to FIG. 2, the portion between themiddle point and the first conversion point has a convex shape, theportion located radially outside of the first conversion point has aconcave shape, and the first conversion point is the point where theportion having a convex shape changes to the portion having a concaveshape, namely the border of two adjacent portions. Alternatively, thereis another common way for a person with ordinary skill in the art totell whether a portion in a vicinity of the optical axis has a convex orconcave shape by referring to the sign of an “R” value, which is the(paraxial) radius of curvature of a lens surface. The R value iscommonly used in conventional optical design software such as Zemax andCodeV. The R value usually appears in the lens data sheet in thesoftware. For an object-side surface, positive R means that theobject-side surface is convex, and negative R means that the object-sidesurface is concave. Conversely, for an image-side surface, positive Rmeans that the image-side surface is concave, and negative R means thatthe image-side surface is convex. The result found by using this methodshould be consistent as by using the other way mentioned above, whichdetermines surface shapes by referring to whether the focal point of acollimated ray is at the object side or the image side.3. For none conversion point cases, the portion in a vicinity of theoptical axis is defined as the portion between 0˜50% of the effectiveradius (radius of the clear aperture) of the surface, whereas theportion in a vicinity of a periphery of the lens element is defined asthe portion between 50˜100% of effective radius (radius of the clearaperture) of the surface.

Referring to the first example depicted in FIG. 3, only one conversionpoint, namely a first conversion point, appears within the clearaperture of the image-side surface of the lens element. Portion I is aportion in a vicinity of the optical axis, and portion II is a portionin a vicinity of a periphery of the lens element. The portion in avicinity of the optical axis is determined as having a concave surfacedue to the R value at the image-side surface of the lens element ispositive. The shape of the portion in a vicinity of a periphery of thelens element is different from that of the radially inner adjacentportion, i.e. the shape of the portion in a vicinity of a periphery ofthe lens element is different from the shape of the portion in avicinity of the optical axis; the portion in a vicinity of a peripheryof the lens element has a convex shape.

Referring to the second example depicted in FIG. 4, a first conversionpoint and a second conversion point exist on the object-side surface(within the clear aperture) of a lens element. In which portion I is theportion in a vicinity of the optical axis, and portion III is theportion in a vicinity of a periphery of the lens element. The portion ina vicinity of the optical axis has a convex shape because the R value atthe object-side surface of the lens element is positive. The portion ina vicinity of a periphery of the lens element (portion III) has a convexshape. What is more, there is another portion having a concave shapeexisting between the first and second conversion point (portion II).

Referring to a third example depicted in FIG. 5, no conversion pointexists on the object-side surface of the lens element. In this case, theportion between 0˜50% of the effective radius (radius of the clearaperture) is determined as the portion in a vicinity of the opticalaxis, and the portion between 50˜100% of the effective radius isdetermined as the portion in a vicinity of a periphery of the lenselement. The portion in a vicinity of the optical axis of theobject-side surface of the lens element is determined as having a convexshape due to its positive R value, and the portion in a vicinity of aperiphery of the lens element is determined as having a convex shape aswell.

As shown in FIG. 6, the optical imaging lens set 1 of six lens elementsof the present invention, sequentially located from an object side 2(where an object is located) to an image side 3 along an optical axis 4,has an aperture stop (ape. stop) 80, a first lens element 10, a secondlens element 20, a third lens element 30, a fourth lens element 40, afifth lens element 50, a sixth lens element 60, a filter 70 and an imageplane 71. Generally speaking, the first lens element 10, the second lenselement 20, the third lens element 30, the fourth lens element 40, thefifth lens element 50 and the sixth lens element 60 may be made of atransparent plastic material but the present invention is not limited tothis and each has an appropriate refractive power. There are exclusivelysix lens elements, which means the first lens element 10, the secondlens element 20, the third lens element 30, the fourth lens element 40,the fifth lens element 50 and the sixth lens element 60, with refractivepower in the optical imaging lens set 1 of the present invention. Theoptical axis 4 is the optical axis of the entire optical imaging lensset 1, and the optical axis of each of the lens elements coincides withthe optical axis of the optical imaging lens set 1.

Furthermore, the optical imaging lens set 1 includes an aperture stop(ape. stop) 80 disposed in an appropriate position. In FIG. 6, theaperture stop 80 is disposed between the object side 2 and the firstlens element 10. When light emitted or reflected by an object (notshown) which is located at the object side 2 enters the optical imaginglens set 1 of the present invention, it forms a clear and sharp image onthe image plane 71 at the image side 3 after passing through theaperture stop 80, the first lens element 10, the second lens element 20,the third lens element 30, the fourth lens element 40, the fifth lenselement 50, the sixth lens element 60 and the filter 70. In oneembodiments of the present invention, the optional filter 70 may be afilter of various suitable functions, for example, the filter 70 may bean infrared cut filter (IR cut filter), placed between the sixth lenselement 60 and the image plane 71. The filter 70 may be made of glass.

Each lens element in the optical imaging lens set 1 of the presentinvention has an object-side surface facing toward the object side 2 aswell as an image-side surface facing toward the image side 3. Forexample, the first lens element 10 has a first object-side surface 11and a first image-side surface 12; the second lens element 20 has asecond object-side surface 21 and a second image-side surface 22; thethird lens element 30 has a third object-side surface 31 and a thirdimage-side surface 32; the fourth lens element 40 has a fourthobject-side surface 41 and a fourth image-side surface 42; the fifthlens element 50 has a fifth object-side surface 51 and a fifthimage-side surface 52; the sixth lens element 60 has a sixth object-sidesurface 61 and a sixth image-side surface 62. In addition, eachobject-side surface and image-side surface in the optical imaging lensset 1 of the present invention has a part (or portion) in a vicinity ofits circular periphery (circular periphery part) away from the opticalaxis 4 as well as a part in a vicinity of the optical axis (optical axispart) close to the optical axis 4.

Each lens element in the optical imaging lens set 1 of the presentinvention further has a central thickness on the optical axis 4. Forexample, the first lens element 10 has a first lens element thicknessT₁, the second lens element 20 has a second lens element thickness T₂,the third lens element 30 has a third lens element thickness T₃, thefourth lens element 40 has a fourth lens element thickness T₄, the fifthlens element 50 has a fifth lens element thickness T₅, the sixth lenselement 60 has a sixth lens element thickness T₆. Therefore, the totalthickness of all the lens elements in the optical imaging lens set 1along the optical axis 4 is ALT=T₁+T₂+T₃+T₄+T₅+T₆.

In addition, between two adjacent lens elements in the optical imaginglens set 1 of the present invention there is an air gap along theoptical axis 4. For example, an air gap AG₁₂ is disposed between thefirst lens element 10 and the second lens element 20, an air gap AG₂₃ isdisposed between the second lens element 20 and the third lens element30, an air gap AG₃₄ is disposed between the third lens element 30 andthe fourth lens element 40, an air gap AG₄₅ is disposed between thefourth lens element 40 and the fifth lens element 50 as well as an airgap AG₅₆ is disposed between the fifth lens element 50 and the sixthlens element 60. Therefore, the sum of total five air gaps betweenadjacent lens elements from the first lens element 10 to the sixth lenselement 60 along the optical axis 4 is AAG=AG₁₂+AG₂₃+AG₃₄+AG₄₅+AG₅₆.

In addition, the distance between the first object-side surface 11 ofthe first lens element 10 to the image plane 71, namely the total lengthof the optical imaging lens set along the optical axis 4 is TTL; theeffective focal length of the optical imaging lens set is EFL; thedistance between the sixth image-side surface 62 of the sixth lenselement 60 to the image plane 71 along the optical axis 4 is BFL.

Furthermore, the focal length of the first lens element 10 is f1; thefocal length of the second lens element 20 is f2; the focal length ofthe third lens element 30 is f3; the focal length of the fourth lenselement 40 is f4; the focal length of the fifth lens element 50 is f5;the focal length of the sixth lens element 60 is f6; the refractiveindex of the first lens element 10 is n1; the refractive index of thesecond lens element 20 is n2; the refractive index of the third lenselement 30 is n3; the refractive index of the fourth lens element 40 isn4; the refractive index of the fifth lens element 50 is n5; therefractive index of the sixth lens element 60 is n6; the Abbe number ofthe first lens element 10 is υ1; the Abbe number of the second lenselement 20 is υ2; the Abbe number of the third lens element 30 is υ3;and the Abbe number of the fourth lens element 40 is υ4; the Abbe numberof the fifth lens element 50 is υ5; and the Abbe number of the sixthlens element 60 is υ6.

First Example

Please refer to FIG. 6 which illustrates the first example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 7A for the longitudinal spherical aberration on the image plane 71of the first example; please refer to FIG. 7B for the astigmatic fieldaberration on the sagittal direction; please refer to FIG. 7C for theastigmatic field aberration on the tangential direction, and pleaserefer to FIG. 7D for the distortion aberration. The Y axis of thespherical aberration in each example is “field of view” for 1.0. The Yaxis of the astigmatic field and the distortion in each example standfor “Half Field of View (HFOV)”, HFOV stands for the half field of viewwhich is half of the field of view of the entire optical lens elementsystem. The Y axis of the astigmatic field and the distortion in eachexample stands for “image height”, which is 2.3 mm.

The optical imaging lens set 1 of the first example has six lenselements 10 to 60 with refractive power. The optical imaging lens set 1also has an aperture stop 80, a filter 70, and an image plane 71. Theaperture stop 80 is provided between the object side 2 and the firstlens element 10. The filter 70 may be used for preventing specificwavelength light (such as the infrared light) reaching the image planeto adversely affect the imaging quality.

The first lens element 10 has positive refractive power. The firstobject-side surface 11 facing toward the object side 2 has a convex part13 in the vicinity of the optical axis and a convex part 14 in avicinity of its circular periphery. The first image-side surface 12facing toward the image side 3 has a convex part 16 in the vicinity ofthe optical axis and a convex part 17 in a vicinity of its circularperiphery. Besides, both the first object-side surface 11 and the firstimage-side 12 of the first lens element 10 are aspherical surfaces.

The second lens element 20 has negative refractive power. The secondobject-side concave surface 21 facing toward the object side 2 has aconvex part 23 in the vicinity of the optical axis and a concave part 24in a vicinity of its circular periphery. The second image-side surface22 facing toward the image side 3 has a concave part 26 in the vicinityof the optical axis and a convex part 27 in a vicinity of its circularperiphery. Both the second object-side surface 21 and the secondimage-side 22 of the second lens element 20 are aspherical surfaces.

The third lens element 30 has positive refractive power. The thirdobject-side surface 31 facing toward the object side 2 has a concavepart 33 in the vicinity of the optical axis and a convex part 34 in avicinity of its circular periphery. The third image-side surface 32facing toward the image side 3 has a convex part 36 in the vicinity ofthe optical axis and a concave part 37 in a vicinity of its circularperiphery. Both the third object-side surface 31 and the thirdimage-side 32 of the third lens element 30 are aspherical surfaces.

The fourth lens element 40 has negative refractive power. The fourthobject-side surface 41 facing toward the object side 2 has a concavepart 43 in the vicinity of the optical axis and a concave part 44 in avicinity of its circular periphery. The fourth image-side surface 42facing toward the image side 3 has a convex part 46 in the vicinity ofthe optical axis and a convex part 47 in a vicinity of its circularperiphery. Both the fourth object-side surface 41 and the fourthimage-side 42 of the fourth lens element 40 are aspherical surfaces.

The fifth lens element 50 has positive refractive power. The fifthobject-side surface 51 facing toward the object side 2 has a convex part53 in the vicinity of the optical axis and a concave part 54 in avicinity of its circular periphery. The fifth image-side surface 52facing toward the image side 3 has a convex part 56 in the vicinity ofthe optical axis and a convex part 57 in a vicinity of its circularperiphery. Both the fifth object-side surface 51 and the fifthimage-side 52 of the fifth lens element 50 are aspherical surfaces.

The sixth lens element 60 has negative refractive power. The sixthobject-side surface 61 facing toward the object side 2 has a concavepart 63 in the vicinity of the optical axis and a convex part 64 in avicinity of its circular periphery. The sixth image-side surface 62facing toward the image side 3 has a concave part 66 in the vicinity ofthe optical axis and a convex part 67 in a vicinity of its circularperiphery. Both the sixth object-side surface 61 and the sixthimage-side 62 of the sixth lens element 60 are aspherical surfaces. Thefilter 70 may be disposed between the sixth image-side 62 of the sixthlens element 60 and the image plane 71.

In the first lens element 10, the second lens element 20, the third lenselement 30, the fourth lens element 40, the fifth lens element 50 andthe sixth lens element 60 of the optical imaging lens element 1 of thepresent invention, the object-side surfaces 11/21/31/41/51/61 andimage-side surfaces 12/22/32/42/52/62 are all aspherical. These asphericcoefficients are defined according to the following formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}\;{a_{2\; i} \times Y^{2\; i}}}}$

In which:

R represents the curvature radius of the lens element surface;

Z represents the depth of an aspherical surface (the perpendiculardistance between the point of the aspherical surface at a distance Yfrom the optical axis and the tangent plane of the vertex on the opticalaxis of the aspherical surface);

Y represents a vertical distance from a point on the aspherical surfaceto the optical axis;

K is a conic constant; a_(2i) is the aspheric coefficient of the 2iorder.

The optical data of the first example of the optical imaging lens set 1are shown in FIG. 26 while the aspheric surface data are shown in FIG.27. In the present examples of the optical imaging lens set, thef-number of the entire optical lens element system is Fno, HFOV standsfor the half field of view which is half of the field of view of theentire optical lens element system, and the unit for the curvatureradius, the thickness and the focal length is in millimeters (mm). Theimage height is 2.3 mm. HFOV is 39.63 degrees.

In FIG. 7A for the longitudinal spherical aberration of the firstexample, the distances amongst the three representing wavelengths arepretty close to one another. It suggests that light of each wavelengthof different heights meets around the imaging point. The inclination ofeach curve suggests that light of different heights meets within a range±0.01 mm so the spherical aberration of different wavelength in thefirst example is greatly improved. In addition, the distances amongstlight of the three representing different wavelengths are small enough.It suggests that light of different wavelengths meets at a small spot sothe field aberration is greatly improved.

In FIGS. 7B and 7C of astigmatic field aberration, light of the threerepresenting different wavelengths in the entire field of view focuseson a spot within ±0.1 mm so it suggests that the optical imaging lensset of the first example is able to effectively eliminate theaberrations. In addition, the distances amongst light of the threerepresenting different wavelengths are small enough. It suggests thatthe optical dispersion on the optical axis 4 is greatly improved. Thedistortion aberration of FIG. 7D reveals that the distortion aberrationof the first example is within a range of ±1%, which suggests thedistortion aberration of the first example meets the demands of theimaging quality of an optical system. Compared with the current opticallens system, the first example shows less aberration/distortion andbetter imaging quality with a system length not greater than 4.0 mm. Thedemonstrated first example may maintain a good optical performance andreduced lens set length to realize a smaller product design.

Some important ratios of the first example are as follows:

AAG/T₂=2.767

AG₃₄/(AG₁₂+AG₄₅)=0.416

ALT/AG₂₃=8.564

T₅/(AG₁₂+AG₄₅)=1.961

(AG₁₂+AG₄₅)/AG₂₃=0.780

ALT/AG₃₄=26.399

T₅/AG₃₄=4.713

T₃/T₅=0.967

ALT/(AG₁₂+AG₄₅)=10.983

T₁/T₃=1.376

T₁/AG₃₄=6.272

T₃/T₆=0.895

AAG/T₅=1.691

T₁/AAG=0.787

T₃/(AG₁₂+AG₄₅)=1.897

T₁/AG₂₃ 2.035

Second Example

Please refer to FIG. 8 which illustrates the second example of theoptical imaging lens set 1 of the present invention. It is noted thatfrom the second example to the following examples, in order to simplifythe figures, only the components different from what the first examplehas, and the basic lens elements will be labeled in figures. Othercomponents that are the same as what the first example has, such as theobject-side surface, the image-side surface, the part in a vicinity ofthe optical axis and the part in a vicinity of its circular peripherywill be omitted in the following examples. Please refer to FIG. 9A forthe longitudinal spherical aberration on the image plane 71 of thesecond example, please refer to FIG. 9B for the astigmatic aberration onthe sagittal direction, please refer to FIG. 9C for the astigmaticaberration on the tangential direction, and please refer to FIG. 9D forthe distortion aberration. The components in the second example aresimilar to those in the first example, but the optical data such as thecurvature radius, the refractive power, the lens thickness, the lensfocal length, the aspheric surface or the back focal length in thisexample are different from the optical data in the first example, and inthis example, the fourth lens element 40 has positive refractive power,the fifth lens element 50 has negative refractive power, the fifthimage-side surface 52 has a concave part 56′ in the vicinity of theoptical axis and a convex part 57 in a vicinity of its circularperiphery, the sixth object-side surface 61 has a convex part 63′ in thevicinity of the optical axis and a concave part 64′ in a vicinity of itscircular periphery. The optical data of the second example of theoptical imaging lens set are shown in FIG. 28 while the aspheric surfacedata are shown in FIG. 29. The image height is 2.3 mm. HFOV is 39.05degrees. Some important ratios of the second example are as follows:

AAG/T₂=2.501

AG₃₄/(AG₁₂+AG₄₅)=0.492

ALT/AG₂₃=11.792

T₅/(AG₁₂+AG₄₅)=2.981

(AG₁₂+AG₄₅)/AG₂₃=0.727

ALT/AG₃₄=32.981

T₅/AG₃₄=6.064

T₃/T₅=0.831

ALT/AG₁₂+AG₄₅)=16.213

T₁/T₃=1.390

T₁/AG₃₄=6.998

T₃/T₆=1.331

AAG/T₅=1.322

T₁/AAG=0.873

T₃/(AG₁₂+AG₄₅)=2.476

T₁/AG₂₃ 2.502

Third Example

Please refer to FIG. 10 which illustrates the third example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 11A for the longitudinal spherical aberration on the image plane 71of the third example; please refer to FIG. 11B for the astigmaticaberration on the sagittal direction; please refer to FIG. 11C for theastigmatic aberration on the tangential direction, and please refer toFIG. 11D for the distortion aberration. The components in the thirdexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the fourth lens element 40 has positive refractivepower, the fifth lens element 50 has negative refractive power, thefifth image-side surface 52 has a concave part 56′ in the vicinity ofthe optical axis and a convex part 57 in a vicinity of its circularperiphery, the sixth lens element 60 has positive refractive power, thesixth object-side surface 61 has a convex part 63′ in the vicinity ofthe optical axis and a concave part 64′ in a vicinity of its circularperiphery. The optical data of the third example of the optical imaginglens set are shown in FIG. 30 while the aspheric surface data are shownin FIG. 31. The image height is 2.3 mm. HFOV is 38.31 degrees. Someimportant ratios of the third example are as follows:

AAG/T₂=2.869

AG₃₄/(AG₁₂+AG₄₅)=0.453

ALT/AG₂₃=9.614

T₅/(AG₁₂+AG₄₅)=1.694

(AG₁₂+AG₄₅)/AG₂₃=0.914

ALT/AG₃₄=23.240

T₅/AG₃₄=3.741

T₃/T₅=1.250

ALT/(AG₁₂+AG₄₅)=10.523

T₁/T₃=1.207

T₁/AG₃₄=5.641

T₃/T₆=1.402

AAG/T₅=1.899

T₁/AAG=0.794

T₃/(AG₁₂+AG₄₅)=2.117

T₁/AG₂₃ 2.334

Fourth Example

Please refer to FIG. 12 which illustrates the fourth example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 13A for the longitudinal spherical aberration on the image plane 71of the fourth example; please refer to FIG. 13B for the astigmaticaberration on the sagittal direction; please refer to FIG. 13C for theastigmatic aberration on the tangential direction, and please refer toFIG. 13D for the distortion aberration. The components in the fourthexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the fourth lens element 40 has positive refractivepower, the fifth lens element 50 has negative refractive power, thefifth image-side surface 52 has a concave part 56′ in the vicinity ofthe optical axis and a convex part 57 in a vicinity of its circularperiphery, the sixth object-side surface 61 has a convex part 63′ in thevicinity of the optical axis and a concave part 64′ in a vicinity of itscircular periphery. The optical data of the fourth example of theoptical imaging lens set are shown in FIG. 32 while the aspheric surfacedata are shown in FIG. 33. The image height is 2.3 mm. HFOV is 38.92degrees. Some important ratios of the fourth example are as follows:

AAG/T₂=3.049

AG₃₄/(AG₁₂+AG₄₅)=0.524

ALT/AG₂₃=8.945

T₅/(AG₁₂+AG₄₅)=1.763

(AG₁₂+AG₄₅)/AG₂₃=0.955

ALT/AG₃₄=17.878

T₅/AG₃₄=3.364

T₃/T₅=0.768

ALT/(AG₁₂+AG₄₅)=9.369

T₁/T₃=1.588

T₁/AG₃₄=4.100

T₃/T₆=1.162

AAG/T₅=1.839

T₁/AAG=0.663

T₃/(AG₁₂+AG₄₅)=1.353

T₁/AG₂₃ 2.051

Fifth Example

Please refer to FIG. 14 which illustrates the fifth example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 15A for the longitudinal spherical aberration on the image plane 71of the fifth example; please refer to FIG. 15B for the astigmaticaberration on the sagittal direction; please refer to FIG. 15C for theastigmatic aberration on the tangential direction, and please refer toFIG. 15D for the distortion aberration. The components in the fifthexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the fourth lens element 40 has positive refractivepower, the fifth lens element 50 has negative refractive power, thefifth image-side surface 52 has a concave part 56′ in the vicinity ofthe optical axis and a convex part 57 in a vicinity of its circularperiphery, the sixth lens element 60 has positive refractive power, thesixth object-side surface 61 has a convex part 63′ in the vicinity ofthe optical axis and a concave part 64′ in a vicinity of its circularperiphery. The optical data of the fifth example of the optical imaginglens set are shown in FIG. 34 while the aspheric surface data are shownin FIG. 35. The image height is 2.3 mm. HFOV is 39.97 degrees. Someimportant ratios of the fifth example are as follows:

AAG/T₂=2.917

AG₃₄/(AG₁₂+AG₄₅)=0.589

ALT/AG₂₃=9.519

T₅/(AG₁₂+AG₄₅)=2.127

(AG₁₂+AG₄₅)/AG₂₃=0.722

ALT/AG₃₄=22.392

T₅/AG₃₄=3.613

T₃/T₅=1.096

ALT/(AG₁₂+AG₄₅)=13.183

T₁/T₃=1.254

T₁/AG₃₄=4.964

T₃/T₆=0.979

AAG/T₅=1.789

T₁/AAG=0.768

T₃/(AG₁₂+AG₄₅)=2.331

T₁/AG₂₃ 2.110

Sixth Example

Please refer to FIG. 16 which illustrates the sixth example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 17A for the longitudinal spherical aberration on the image plane 71of the sixth example; please refer to FIG. 17B for the astigmaticaberration on the sagittal direction; please refer to FIG. 17C for theastigmatic aberration on the tangential direction, and please refer toFIG. 17D for the distortion aberration. The components in the sixthexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the first image-side surface 12 has a concave part16′ in the vicinity of the optical axis and a convex part 17 in avicinity of its circular periphery, the third object-side surface 31 ofthe third lens element 30 has a convex part 33′ in the vicinity of theoptical axis, a convex part 34 in a vicinity of its circular peripheryand a concave part 35 between the optical axis and the circularperiphery part, the fifth image-side surface 52 has a concave part 56′in the vicinity of the optical axis and a convex part 57 in a vicinityof its circular periphery, the sixth object-side surface 61 has a convexpart 63′ in the vicinity of the optical axis, a convex part 64 in avicinity of its circular periphery and a concave part 65 between theoptical axis and the circular periphery part. The optical data of thesixth example of the optical imaging lens set are shown in FIG. 36 whilethe aspheric surface data are shown in FIG. 37. The image height is 2.3mm. HFOV is 40.99 degrees. Some important ratios of the sixth exampleare as follows:

AAG/T₂=3.310

AG₃₄/(AG₁₂+AG₄₆)=0.237

ALT/AG₂₃=21.355

T₅/(AG₁₂+AG₄₆)=1.140

(AG₁₂+AG₄₆)/AG₂₃=3.645

ALT/AG₃₄=24.722

T₅/AG₃₄=4.809

T₃/T₅=1.243

ALT/(AG₁₂+AG₄₆)=5.858

T₁/T₃=0.771

T₁/AG₃₄=4.611

T₃/T₆=1.520

AAG/T₅=1.420

T₁/AAG=0.675

T₃/(AG₁₂+AG₄₅)=1.417

T₁/AG₂₃ 3.983

Seventh Example

Please refer to FIG. 18 which illustrates the seventh example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 19A for the longitudinal spherical aberration on the image plane 71of the seventh example; please refer to FIG. 19B for the astigmaticaberration on the sagittal direction; please refer to FIG. 19C for theastigmatic aberration on the tangential direction, and please refer toFIG. 19D for the distortion aberration. The components in the seventhexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the third object-side surface 31 of the third lenselement 30 has a convex part 33′ in the vicinity of the optical axis anda convex part 34 in a vicinity of its circular periphery and a concavepart 35 between the optical axis and the circular periphery part, thefourth lens element 40 has negative refractive power, the fourthobject-side surface 41 has a concave part 43 in the vicinity of theoptical axis and a concave part 44 in a vicinity of its circularperiphery and a convex part 45 between the optical axis and the circularperiphery part, the fifth image-side surface 52 has a concave part 53′in the vicinity of the optical axis and a convex part 54′ in a vicinityof its circular periphery, the sixth object-side surface 61 has a convexpart 63′ in the vicinity of the optical axis and a concave part 64′ in avicinity of its circular periphery. The optical data of the seventhexample of the optical imaging lens set are shown in FIG. 38 while theaspheric surface data are shown in FIG. 39. The image height is 2.3 mm.HFOV is 40.99 degrees. Some important ratios of the seventh example areas follows:

AAG/T₂=2.071

AG₃₄/(AG₁₂+AG₄₅)=1.097

ALT/AG₂₃=16.775

T₅/(AG₁₂+AG₄₅)=1.988

(AG₁₂+AG₄₆)/AG₂₃=0.795

ALT/AG₃₄=19.229

T₅/AG₃₄=1.812

T₃/T₅=1.896

ALT/(AG₁₂+AG₄₆)=21.095

T₁/T₃=1.176

T₁/AG₃₄=4.042

T₃/T₆=0.815

AAG/T₅=2.322

T₁/AAG=0.961

T₃/(AG₁₂+AG₄₆)=3.769

T₁/AG₂₃ 3.526

Eighth Example

Please refer to FIG. 20 which illustrates the eighth example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 21A for the longitudinal spherical aberration on the image plane 71of the eighth example; please refer to FIG. 21B for the astigmaticaberration on the sagittal direction; please refer to FIG. 21C for theastigmatic aberration on the tangential direction, and please refer toFIG. 21D for the distortion aberration. The components in the eighthexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the first image-side surface 12 has a concave part16′ in the vicinity of the optical axis and a convex part 17 in avicinity of its circular periphery, the third object-side surface 31 ofthe third lens element 30 has a convex part 33′ in the vicinity of theoptical axis, a concave part 34′ in a vicinity of its circularperiphery, the fourth image-side surface 42 has a convex part 46 in thevicinity of the optical axis and a concave part 47′ in a vicinity of itscircular periphery, the fifth image-side surface 52 has a concave part56′ in the vicinity of the optical axis and a convex part 57 in avicinity of its circular periphery, the eighth object-side surface 61has a convex part 63′ in the vicinity of the optical axis and a concavepart 64′ in a vicinity of its circular periphery. The optical data ofthe eighth example of the optical imaging lens set are shown in FIG. 40while the aspheric surface data are shown in FIG. 41. The image heightis 2.3 mm. HFOV is 40.00 degrees. Some important ratios of the eighthexample are as follows:

AAG/T₂=2.829

AG₃₄/(AG₁₂+AG₄₆)=1.489

ALT/AG₂₃=14.842

T₅/(AG₁₂+AG₄₆)=2.640

(AG₁₂+AG₄₆)/AG₂₃=1.064

ALT/AG₃₄=9.372

T₅/AG₃₄=1.773

T₃/T₅=0.913

ALT/(AG₁₂+AG₄₆)=13.954

T₁/T₃=1.437

T₁/AG₃₄=2.326

T₃/T₆=1.061

AAG/T₅=1.517

T₁/AAG=0.865

T₃/(AG₁₂+AG₄₆)=2.410

T₁/AG₂₃ 3.683

Ninth Example

Please refer to FIG. 22 which illustrates the ninth example of theoptical imaging lens set 1 of the present invention. Please refer toFIG. 23A for the longitudinal spherical aberration on the image plane 71of the ninth example; please refer to FIG. 23B for the astigmaticaberration on the sagittal direction; please refer to FIG. 23C for theastigmatic aberration on the tangential direction, and please refer toFIG. 23D for the distortion aberration. The components in the ninthexample are similar to those in the first example, but the optical datasuch as the curvature radius, the refractive power, the lens thickness,the lens focal length, the aspheric surface or the back focal length inthis example are different from the optical data in the first example,and in this example, the second object-side concave surface 21 has aconcave part 23′ in the vicinity of the optical axis and a concave part24 in a vicinity of its circular periphery, the third object-sidesurface 31 of the third lens element 30 has a convex part 33′ in thevicinity of the optical axis and a convex part 34 in a vicinity of itscircular periphery and a concave part 35 between the optical axis andthe circular periphery part, the fourth image-side surface 42 has aconvex part 46 in the vicinity of the optical axis and a concave part47′ in a vicinity of its circular periphery, the fifth object-sidesurface 51 has a concave part 53′ in the vicinity of the optical axisand a concave part 54 in a vicinity of its circular periphery, the sixthobject-side surface 61 has a concave part 63 in the vicinity of theoptical axis and a concave part 64′ in a vicinity of its circularperiphery. The optical data of the ninth example of the optical imaginglens set are shown in FIG. 42 while the aspheric surface data are shownin FIG. 43. The image height is 2.3 mm. HFOV is 40.00 degrees. Someimportant ratios of the ninth example are as follows:

AAG/T₂=3.643

AG₃₄/(AG₁₂+AG₄₅)=1.344

ALT/AG₂₃=17.102

T₅/(AG₁₂+AG₄₅)=1.762

(AG₁₂+AG₄₅)/AG₂₃=1.181

ALT/AG₃₄=10.769

T₅/AG₃₄=1.311

T₃/T₅=1.556

ALT/(AG₁₂+AG₄₅)=14.476

T₁/T₃=1.332

T₁/AG₃₄=2.718

T₃/T₆=0.919

AAG/T₅=1.987

T₁/AAG=1.043

T₃/(AG₁₂+AG₄₅)=2.742

T₁/AG₂₃ 4.315

Some important ratios in each example are shown in FIG. 44. The distancebetween the sixth image-side surface 62 of the sixth lens element 60 tothe filter 70 along the optical axis 4 is G6F; the thickness of thefilter 70 along the optical axis 4 is TF; the distance between thefilter 70 to the image plane 71 along the optical axis 4 is GFI; thedistance between the sixth image-side surface 62 of the sixth lenselement 60 to the image plane 71 along the optical axis 4 is BFL.Therefore, BFL=G6F+TF+GFI.

In the light of the above examples, the inventors observe at least thefollowing features:

1. The positive refractive power of the first lens element provides thepositive refractive power for the entire optical imaging lens set 1. Thenegative refractive power of the second lens element helps correct theentire aberration of the optical system. The aperture stop is disposedin front of the first object-side surface to improve the imaging qualityand to decrease the length of the entire optical imaging lens set.2. The first object-side surface with a convex part in a vicinity of theoptical axis and of its circular periphery helps collect the imaginglight, the collective match of the first image-side surface with aconvex part in a vicinity of its circular periphery, the secondobject-side surface with a concave part in the vicinity of its circularperiphery, the third image-side surface with a concave part in avicinity of its circular periphery, the fourth image-side surface with aconvex part in the vicinity of the optical axis, the fifth object-sidesurface with a concave part in a vicinity of its circular periphery, thesixth image-side surface with a concave part in the vicinity of theoptical axis and a convex part in a vicinity of its circular peripheryenhances the imaging quality, to decrease the total length, to decreasethe f-number and to enlarge the field of view of the optical system.

In addition, the inventors discover that there are some better ratioranges for different data according to the above various importantratios. Better ratio ranges help the designers to design a betteroptical performance and an effectively reduce length of a practicallypossible optical imaging lens set. For example:

1. The ratio of AAG/T₂ is suggested to be less than or equal to 3.6, andpreferably between 2.0˜3.6.

2. The ratio of AG₃₄/(AG₁₂+AG₄₅) is suggested to be less than or equalto 1.5, and preferably between 0.2˜1.5.

3. The ratio of ALT/AG₂₃ is suggested to be more than or equal to 8.5,and preferably between 8.5˜25.0.

4. The ratio of T₅/(AG₁₂+AG₄₅) is suggested to be less than or equal to3.0, and preferably between 0.8˜3.0.

5. The ratio of (AG₁₂+AG₄₅)/AG₂₃ is suggested to be more than or equalto 0.7, and preferably between 0.7˜4.0.

6. The ratio of ALT/AG₃₄ is suggested to be more than or equal to 9.0,and preferably between 9.0˜35.0.

7. The ratio of T₅/AG₃₄ is suggested to be more than or equal to 1.3,and preferably between 1.3˜7.0.

8. The ratio of T₃/T₅ is suggested to be more than or equal to 0.75, andpreferably between 0.75˜2.5.

9. The ratio of ALT/(AG₁₂+AG₄₅) is suggested to be more than or equal to9.0, and preferably between 9.0˜25.0.

10. The ratio of T₁/T₃ is suggested to be less than or equal to 1.6, andpreferably between 0.5˜1.6.

11. The ratio of T₁/AG₃₄ is suggested to be more than or equal to 2.3,and preferably between 2.3˜8.0.

12. The ratio of T₃/T₆ is suggested to be more than or equal to 0.8, andpreferably between 0.8˜2.0.

13. The ratio of AAG/T₅ is suggested to be less than or equal to 2.0,and preferably between 1.0˜2.0.

14. The ratio of T₁/AAG is suggested to be more than or equal to 0.65,and preferably between 0.65˜1.2.

15. The ratio of T₃/(AG₁₂+AG₄₅) is suggested to be more than or equal to1.3, and preferably between 1.3˜5.0.

16. The ratio of T₁/AG₂₃ is suggested to be more than or equal to 2.0,and preferably between 2.0˜5.0.

The optical imaging lens set 1 of the present invention may be appliedto an electronic device, such as mobile phones or driving recorders.Please refer to FIG. 24. FIG. 24 illustrates a first preferred exampleof the optical imaging lens set 1 of the present invention for use in aportable electronic device 100. The electronic device 100 includes acase 110, and an image module 120 mounted in the case 110. A drivingrecorder is illustrated in FIG. 24 as an example, but the electronicdevice 100 is not limited to a driving recorder.

As shown in FIG. 24, the image module 120 includes the optical imaginglens set 1 as described above. FIG. 24 illustrates the aforementionedfirst example of the optical imaging lens set 1. In addition, theportable electronic device 100 also contains a barrel 130 for theinstallation of the optical imaging lens set 1, a module housing unit140 for the installation of the barrel 130, a substrate 172 for theinstallation of the module housing unit 140 and an image sensor 72disposed at the substrate 172, and at the image side 3 of the opticalimaging lens set 1. The image sensor 72 in the optical imaging lens set1 may be an electronic photosensitive element, such as a charge coupleddevice or a complementary metal oxide semiconductor element. The imageplane 71 forms at the image sensor 72.

The image sensor 72 used here is a product of chip on board (COB)package rather than a product of the conventional chip scale package(CSP) so it is directly attached to the substrate 172, and protectiveglass is not needed in front of the image sensor 72 in the opticalimaging lens set 1, but the present invention is not limited to this.

To be noticed in particular, the optional filter 70 may be omitted inother examples although the optional filter 70 is present in thisexample. The case 110, the barrel 130, and/or the module housing unit140 may be a single element or consist of a plurality of elements, butthe present invention is not limited to this.

Each one of the six lens elements 10, 20, 30, 40, 50 and 60 withrefractive power is installed in the barrel 130 with air gaps disposedbetween two adjacent lens elements in an exemplary way. The modulehousing unit 140 has a lens element housing 141, and an image sensorhousing 146 installed between the lens element housing 141 and the imagesensor 72. However in other examples, the image sensor housing 146 isoptional. The barrel 130 is installed coaxially along with the lenselement housing 141 along the axis I-I′, and the barrel 130 is providedinside of the lens element housing 141.

Please also refer to FIG. 25 for another application of theaforementioned optical imaging lens set 1 in a portable electronicdevice 200 in the second preferred example. The main differences betweenthe portable electronic device 200 in the second preferred example andthe portable electronic device 100 in the first preferred example are:the lens element housing 141 has a first seat element 142, a second seatelement 143, a coil 144 and a magnetic component 145. The first seatelement 142 is for the installation of the barrel 130, exteriorlyattached to the barrel 130 and disposed along the axis I-I′. The secondseat element 143 is disposed along the axis I-I′ and surrounds theexterior of the first seat element 142. The coil 144 is provided betweenthe outside of the first seat element 142 and the inside of the secondseat element 143. The magnetic component 145 is disposed between theoutside of the coil 144 and the inside of the second seat element 143.

The first seat element 142 may pull the barrel 130 and the opticalimaging lens set 1 which is disposed inside of the barrel 130 to movealong the axis I-I′, namely the optical axis 4 in FIG. 6. The imagesensor housing 146 is attached to the second seat element 143. Thefilter 70, such as an infrared filter, is installed at the image sensorhousing 146. Other details of the portable electronic device 200 in thesecond preferred example are similar to those of the portable electronicdevice 100 in the first preferred example so they are not elaboratedagain.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An optical imaging lens set, from an object sidetoward an image side in order along an optical axis comprising: anaperture stop, a first lens element with positive refractive power, asecond lens element with negative refractive power, a third lenselement, a fourth lens element, a fifth lens element and a sixth lenselement, said first lens element to said sixth lens element each havingan object-side surface facing toward the object side as well as animage-side surface facing toward the image side, wherein: said firstlens element has positive refractive power, an object-side surface witha convex portion in a vicinity of said optical axis and a convex portionin a vicinity of its periphery, and an image-side surface with a convexportion in a vicinity of its periphery; said second lens element hasnegative refractive power and an object-side surface with a concaveportion in a vicinity of its periphery; said third lens element has animage-side surface with a concave portion in a vicinity of itsperiphery; said fourth lens element has an image-side surface with aconvex portion in a vicinity of the optical axis; said fifth lenselement has an object-side surface with a concave portion in a vicinityof its periphery; and said sixth lens element has an image-side surfacewith a concave portion in a vicinity of the optical axis and a convexportion in a vicinity of its periphery, and the sum of all five air gapsAAG between each lens elements from said first lens element to saidsixth lens element along the optical axis and a second lens elementthickness T₂ satisfy AAG/T₂≦3.6.
 2. The optical imaging lens set ofclaim 1, wherein a total thickness ALT of said first lens element, saidsecond lens element, said third lens element, said fourth lens element,said fifth lens element and said sixth lens element along said opticalaxis and an air gap AG₂₃ between said second lens element and said thirdlens element along said optical axis satisfy a relationship8.5≦ALT/AG₂₃.
 3. The optical imaging lens set of claim 2, wherein athickness T₁ of said first lens element along said optical axis and anair gap AG₃₄ between said third lens element and said fourth lenselement along said optical axis satisfy a relationship 2.3≦T₁/AG₃₄. 4.The optical imaging lens set of claim 1, wherein a thickness T₅ of saidfifth lens element along said optical axis, an air gap AG₁₂ between saidfirst lens element and said second lens element along said optical axisand an air gap AG₄₅ between said fourth lens element and said fifth lenselement along said optical axis satisfy a relationshipT₅/(AG₁₂+AG₄₅)≦3.0.
 5. The optical imaging lens set of claim 4, whereina thickness T₃ of said third lens element along said optical axis and athickness T₆ of said sixth lens element along said optical axis satisfya relationship 0.8≦T₃/T₆.
 6. The optical imaging lens set of claim 4,satisfying a relationship AAG/T₅≦2.0.
 7. The optical imaging lens set ofclaim 1, wherein an air gap AG₁₂ between said first lens element andsaid second lens element along said optical axis, an air gap AG₂₃between said second lens element and said third lens element along saidoptical axis and an air gap AG₄₅ between said fourth lens element andsaid fifth lens element along said optical axis satisfy a relationship0.7≦(AG₁₂+AG₄₅)/AG₂₃.
 8. The optical imaging lens set of claim 7,wherein a thickness T₁ of said first lens element along said opticalaxis satisfies a relationship 0.65≦T₁/AAG.
 9. The optical imaging lensset of claim 1, wherein a total thickness ALT of said first lenselement, said second lens element, said third lens element, said fourthlens element, said fifth lens element and said sixth lens element alongsaid optical axis and an air gap AG₃₄ between said third lens elementand said fourth lens element along said optical axis satisfy arelationship 9.0≦ALT/AG₃₄.
 10. The optical imaging lens set of claim 9,wherein a thickness T₃ of said third lens element along said opticalaxis, an air gap AG₁₂ between said first lens element and said secondlens element along said optical axis and an air gap AG₄₅ between saidfourth lens element and said fifth lens element along said optical axissatisfy a relationship 1.3≦T₃/(AG₁₂+AG₄₅).
 11. The optical imaging lensset of claim 1, wherein an air gap AG₁₂ between said first lens elementand said second lens element along said optical axis, an air gap AG₃₄between said third lens element and said fourth lens element along saidoptical axis and an air gap AG₄₅ between said fourth lens element andsaid fifth lens element along said optical axis satisfy a relationshipAG₃₄/(AG₁₂+AG₄₅)≦1.5.
 12. The optical imaging lens set of claim 11,wherein a thickness T₃ of said third lens element along said opticalaxis and a thickness T₅ of said fifth lens element along said opticalaxis satisfy a relationship 0.75≦T₃/T₅.
 13. The optical imaging lens setof claim 12, wherein a total thickness ALT of said first lens element,said second lens element, said third lens element, said fourth lenselement, said fifth lens element and said sixth lens element along saidoptical axis, an air gap AG₁₂ between said first lens element and saidsecond lens element along said optical axis and an air gap AG₄₅ betweensaid fourth lens element and said fifth lens element along said opticalaxis satisfy a relationship 9.0≦ALT/(AG₁₂+AG₄₅).
 14. The optical imaginglens set of claim 12, wherein a thickness T₁ of said first lens elementalong said optical axis satisfy a relationship T₁/T₃≦1.6.
 15. Theoptical imaging lens set of claim 1, wherein a thickness T₅ of saidfifth lens element along said optical axis and an air gap AG₃₄ betweensaid third lens element and said fourth lens element along said opticalaxis satisfy a relationship 1.3≦T₅/AG₃₄.
 16. The optical imaging lensset of claim 15, wherein a thickness T₁ of said first lens element alongsaid optical axis and an air gap AG₂₃ between said second lens elementand said third lens element along said optical axis satisfies arelationship 2.0≦T₁/AG₂₃.
 17. The optical imaging lens set of claim 16,wherein a thickness T₅ of said fifth lens element along said opticalaxis, an air gap AG₁₂ between said first lens element and said secondlens element along said optical axis and an air gap AG₄₅ between saidfourth lens element and said fifth lens element along said optical axissatisfy a relationship T₅/(AG₁₂+AG₄₅)≦3.0.
 18. An electronic device,comprising: a case; and an image module disposed in said case andcomprising: an optical imaging lens set of claim 1; a barrel for theinstallation of said optical imaging lens set; a module housing unit forthe installation of said barrel; a substrate for the installation ofsaid module housing unit; and an image sensor disposed at an image sideof said optical imaging lens set.